The goal of this project is to define the properties of muscarinic and nicotinic acetylcholine receptors and acetylcholinesterase during development of chick embryo retina. Thus far we have elucidated (1) the specificity and affinities of muscarinic and nicotinic acetylcholine receptors for receptor activation and antagonists, (2) the number of receptors were defined as a function of developmental age of the retina, and (3) the location of nicotinic and muscarinic receptors within the retina was determined.